Battery: Will it be upgradeable in the future?

Dumb Question?
Will there be an option in the future to replace an existing battery with a higher charge battery? I have heard of 120KW in the future.
What kind of implications does that have?
Will you be able to upgrade a larger battery into your existing car? Which car, i.e. 60Kw 85KW 85KW perf can take this ?new larger batter? What would the new battery imply regarding speed?
Thanks in advance

No, you will not be able to replace your current battery with a different size battery. We recommend configuring your Model S today with the battery that will meet your current, as well as future range needs.

Dumb Question?
Will there be an option in the future to replace an existing battery with a higher charge battery? I have heard of 120KW in the future.
What kind of implications does that have?
Will you be able to upgrade a larger battery into your existing car? Which car, i.e. 60Kw 85KW 85KW perf can take this ?new larger batter? What would the new battery imply regarding speed?
Thanks in advance